THE MUSCULATURE OF THE TRUNK. 261 



Telcosts among fishes they form a bulky mass that goes 

 to he inserted at the back of the cranium. 



No less interesting is the study of the group of 

 caudal muscles in this Raven, as compared with several 

 of the forms suggested above. In a bird as high in 

 the scale of organization as our present subject, of 

 course, these muscles now all subserve the special 

 movements of no less important an instrument to 

 the performance of flight than the tail. With many of 

 our existing Lizards, however, the tail must be consi- 



o 



dered more in the light of an ornament rather than an 

 essential part in the economy. For instance, our little 

 Anolis seems to get along quite as well when this 

 appendage is broken off short with his body as he 

 does with it ; whereas I dare say such a curtailment 

 in the Archcso'pteryx of the Jurassic would have proved 

 a very serious accident, if not a fatal one in many 

 cases. 



Again, even in the Mammalia, as in the ring-tailed 

 Monkeys, we find the tail a very useful and important 

 organ, and in them the caudal muscles and their ten- 

 dons are powerfully developed to meet the special ends 

 of the act of caudal prehension. 



Splendid demonstrations of this group of muscles in 

 existing Lizards are to be seen in Mr. Mivart's memoir 

 "On the Myology of Chamceleon parsonii'' (P.Z.S., 

 December 6, 1870, p. 850), and his "Myology of 

 Iguana tuber culata" (Hid., 1867, p. 766); as well as 

 in Mr. Alfred Sanders's "Myology of Liolepis belli' 

 (P.Z.S., 1872, p. 154), and the " Myology of Phryno- 

 soma coronatum," by the same author (P.Z.S., 1874, 

 p. 71). 



In speaking of these muscles in a general way, Mivart 

 says that " A whole series of muscles may be developed 



